NOTE: I have used Velveeta as it is hard to find the block American cheese.
In a 3 qt. saucepan, brown beef: drain and set aside. In the same saucepan, sauté onion, carrots, celery, basil and parsley in 1 T. butter until vegetables are tender, about 10 minutes. Add broth, potatoes and beef, bring to a boil. Reduce heat; cover and simmer for 10-12 minutes or until potatoes are tender. Meanwhile, in a small skillet, melt remaining butter. Add flour; cook and stir for 3-5 minutes or until bubbly. Add to soup; bring to a boil. Cook and stir for 2 minutes. Reduce heat to low. Add cheese, milk, salt and pepper; cook and stir until cheese melts.
Remove from heat; blend in sour cream. Yield: 8 servings (2 1/4 quarts). ENJOY!!